JPS5890949A - Sheet for packing electronic part - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a packaging sheet, and more particularly to a sheet for packaging electronic components.

Electronic components that are sensitive to static electricity, such as semiconductors, are easily damaged by static electricity before they are attached to electronic circuits, and even after they are attached to electronic circuits, which poses a major problem. , to protect electronic components from static electricity,
Plastic films and metal foils mixed with conductive substances such as carbon and metal powder are used as packaging materials for electronic components.

However, since all of these are opaque, it is impossible to confirm the existence and damage of the electronic components inside, or to identify the type.On the other hand, plastic films mixed with antistatic agents are However, these have considerably high electrical resistance per unit area and are completely inadequate for protecting electronic components.Depending on the type of antistatic agent, they are easily affected by moisture and lack stability. .

The present invention eliminates the above-mentioned drawbacks, and provides a sheet for packaging electronic components that allows the electronic components contained in the package to be seen through and is sufficient to protect the electronic components from static electricity. Furthermore, the present invention provides an extremely convenient, useful, and novel sheet for packaging electronic components that can be heat-sealed on both the front and back sides. A thin metal film is provided on both the front and back sides of a transparent plastic film.

B) The light transmittance of the metal thin film is 25 or more when the light passes through the metal thin films on both the front and back sides.The electric resistance per unit area of the metal thin film is 108Ω or less.

D) The thickness of the metal thin film is 101-250A.

E) A transparent protective layer containing an antistatic agent or not containing an antistatic agent is provided on the metal thin film to a thickness of 1 μm or less, if necessary.

This is an electronic component packaging sheet that is heat-sealable on both the front and back sides, and is characterized by meeting the requirements A) to E) above.

Next, the present invention will be explained with reference to the drawings.

Both FIG. 1 and FIG. 2 are partially enlarged cross-sectional views showing one embodiment of the electronic component packaging sheet of the present invention, and FIG. It is a partially cutaway perspective view when the package is formed.

In the figure, 1 is a transparent plastic film with heat-sealing properties on both the front and back surfaces, 2 is a metal thin film,
3 is a transparent protective layer, and 4 is a heat seal portion.

The transparent plastic film 1, which has heat-sealability on both the front and back sides, may be a polyethylene film, an ionomer resin film, an ethylene-vinyl acetate copolymer film, an unstretched polypropylene film, a vinyl chloride film, etc. The plastic film itself has heat-sealability. If it is, you can use it as is.

The transparent plastic film 1, which has heat-sealing properties on both the front and back sides, may also include polyester film, acrylic film, vinyl chloride film, fluorocarbon film,
It can also be obtained by providing a transparent heat-sealable layer on both the front and back sides of a styrene film, polypropylene film, polyethylene film, or other transparent plastic film that can be used as a packaging material. This heat-sealable layer can be provided by laminating polyethylene or other heat-sealable films on the plastic film, or by extrusion laminating or coating a resin such as polyethylene. Examples of resins that can be used in the heat-sealable layer include polyethylene, soft vinyl chloride, modified polyester, KVA, and various other heat-sealable resins. The heat-sealing layer can also be provided not over the entire surface, but only in the areas where heat-sealing is actually performed.

The metal thin film 2 is formed on both the front and back surfaces of the transparent plastic film 1 having heat-sealing properties by a conventionally known thin film production method such as a vacuum evaporation method, a sputtering method, an ion blating method, or an electron beam evaporation method. It is being

Note that in this specification, a metal thin film includes any of a thin film made of a single metal, a thin film made of an alloy, and a thin film made of a metal compound such as a metal oxide, as long as it has conductivity.

The metal thin film 2 includes Cr, Ni, A4, Fe, In, A+
g, Au, Cu, 3n, Zn, Ti1Ni-C
r, engineering n20. Any material capable of forming a thin film can be used.

The metal thin film 2 must satisfy the following conditions: a light transmittance of 25% or more when light passes through the metal thin films on both the front and back surfaces, an electrical resistance per unit area of 108 Ω or less, and a film thickness of 10 to 250 λ. These conditions of light transmittance, electrical resistance, and film thickness are essential to achieving the object of the present invention.

That is, if the light transmittance in the above case is lower than 25 inches, it will be difficult to see through the electronic components inside the package.

Furthermore, if the electrical resistance of the metal thin film is as high as 10 8 Ω, the conductivity will be poor and it will be insufficient to protect electronic components from static electricity charging.

The film thickness shows the relationship with light transmittance and electrical resistance, and also shows the relationship with heat seal.

If the film thickness is outside the range of 10X to 250X, the conditions of light transmittance of 25% or more and electrical resistance per unit area of 108Ω or less cannot be met. If the film thickness is thinner than IOA, the electrical resistance tends to be higher than 108 Ω depending on the metal, and the protection of electronic components becomes insufficient. If the film is thicker than 25OA, it depends on the metal.

In this case, the light transmittance becomes lower than 25%, making it difficult to see through the electronic components inside.

In this way, the light transmittance, electrical resistance per unit area, and film thickness of the metal thin film 2 in the above case are closely related to each other, and the metal thin film 2 satisfies all of these three conditions. The thickness of the thin metal film 2 that needs to be formed is also of critical importance when forming the package by heat sealing. When the thickness of the metal thin film 2 is 250λ or less, it is extremely thin and does not particularly affect heat sealing, and heat sealing is possible in the same way as in the case where the metal thin film 2 is not present. However, if the metal thin film 2 exceeds 250A, it is no longer possible to perform heat sealing sufficiently.

In this invention, a package is formed by heat-sealing both the front and back sides, and electronic components are packaged in the package.

In this invention, the electrical resistance per unit area of the metal thin film 2 is 1.
Since it has a conductivity of 0Ω or less, it can sufficiently protect electronic components from static electricity generated inside and outside the packaging. especially,
Since the metal thin film 2 is present on the surface of both the inside and outside of the package, the influence of static electricity can be almost completely eliminated.

Furthermore, since both the front and back surfaces of the present invention can be heat-sealed, it has the following extremely convenient and beneficial effects in addition to the above-mentioned effects and advantages.

■ Conventional products can only be heat-sealed on one side, so when heat-sealing, it is necessary to check in advance to confirm which side is the one that can be heat-sealed.
The present invention does not require such confirmation of the heat seal surface.

■ No errors in setting the front and back sides during automatic bag making; therefore, work efficiency is greatly improved.

■ Heat sealing can be done on either the same side or on opposite sides in any combination of back stickers, envelope stickers, side stickers, etc.

■ Since heat sealing can be performed in any combination on the front and back sides, it is extremely easy to increase the width of the sheet by heat sealing.

■ By stacking multiple sheets and heat-sealing them, the sheets can be assembled firmly.

In the present invention, a film containing an antistatic agent can also be used as the transparent plastic film 1 having heat sealability.

Further, in the present invention, a transparent protective layer 6 made of a suitable resin can be provided on the metal thin film 2, and in this case, the protective layer 2 can also contain an antistatic agent. However, the protective layer 6 needs to be extremely thin, with a thickness of 1 μm or less.

This is because if the thickness of the protective layer 6 exceeds 1μ, it will have some effect on the removal of static electricity and heat sealing since it exists on the surface. If it is less than 1μ, it is extremely thin, so it has almost no effect on static electricity removal or heat sealing, and even if it does, it is so small that it can be ignored for electronic component packaging. be.

It should be noted that this invention can naturally be colored or printed as appropriate, and this invention also includes those that are colored or printed at appropriate locations.

Example 1 A Cr vapor deposited film with a light transmittance of 78%, an electrical resistance per unit area of 6 x 10 Ω, and a film thickness of 50 λ was formed on one side of a transparent polyethylene film with a thickness of 40 μ by vacuum deposition. On the other side of the polyethylene film, a Cr vapor deposited film having a light transmittance of 80 cm, an electrical resistance per unit area of 1.5 x lO'Ω, and a film thickness of 40 A was formed by the same vacuum deposition method. The light transmittance of the entire sheet-like material was about 61 yen.Next, using the sheet-like material obtained in this way, packaging A was prepared with the side with the Cr film thickness of 5OA on the outside, and package A with the Cr film thickness of 40A was used. Packaging B with the side facing outward was formed by heat sealing.

Example 2 Both sides of a transparent ionomer resin film with a thickness of 40 μm were coated by vacuum evaporation, with a light transmittance of 75%, an electrical resistance per unit area of 4×11]5Ω, and a film thickness of 50AL.
A vNi vapor deposited film was formed. Next, on the N1 vapor deposited film on both sides,
The antistatic agent is O, +% gold-containing transparent resin paint.
．． A protective layer with a thickness of 2μ was formed. The light transmittance of the entire sheet-like material thus obtained was about 50.

Next, the sheet-like product obtained in this way was used to form a package C by heat sealing.

Example 6 A heat-sealable polyester film having a transparent modified polynisder layer on both sides of a transparent polyester film with a thickness of 25 μm was coated with a multi-light transmittance of 50 μm and an electric current per unit area by electron beam evaporation on one side. A Cr vapor-deposited film having a resistance of 4×10′Ω and a thickness of 120λ was formed. Next, on the other side of the heat-sealable polyester film, a Cr vapor-deposited film having a light transmittance of 60 cm, an electrical resistance per unit area of 2×10 5 Ω, and a film thickness of 6 OA was formed by the same electron beam evaporation method. The light transmittance of the entire sheet-like material thus obtained was about 60%.

Next, using the sheet-like material obtained in this way, a package with the side with the Cr film thickness of 120^ on the outside and a package E with the side with the Cr film thickness of 60^ on the outside were formed by heat sealing. Next, a comparative example with a conventional product is shown.0 As a comparative example, sample 1 is a heat-sealable non-static polyethylene packaging (pink plastic bag manufactured by Tokyo Denki Kagaku Kogyo Co., Ltd.) that has been commercially available. A package made by laminating a polyester film and a polyethylene film was used as Sample 2.

Packaging A-E obtained in Examples 1 to 6, Samples 1 and 2
A liquid crystal panel was enclosed in each package.

Next, 10CI11 for each package containing the liquid crystal board.
The presence or absence of disorder in the letters and numbers in the liquid crystal panel was examined by irradiating ions of ■ and e with a static electricity generator (Z11iRO8TAT) of 8000 V to +oooo v from a distance of . The transparency of the packaging was also compared.The results are shown in the table below.

In addition, ○... No disturbance at all.

×・・・Very disturbed.

As is clear from the results in the table, when the electronic component packaging sheet of the present invention is used, there is no disturbance in the letters and numbers of Pushimane, and the protection from static electricity is extremely significant compared to conventional products. It has the following effects.

[Brief explanation of the drawing]

Both FIG. 1 and FIG. 2 are partially enlarged sectional views showing one embodiment of the electronic component packaging sheet of the present invention, and FIG. 5 is a partially enlarged sectional view showing an embodiment of the electronic component packaging sheet of FIG. FIG. 1... Transparent plastic film with heat-sealable properties on both sides 2... Metal thin film 3... Transparent protective layer 4... Patent application for heat-sealing part Hito Co., Ltd. Reiko Figure 3

Claims (1)

[Scope of Claims] A) Metal thin films are provided on both the front and back surfaces of a transparent plastic film that has heat sealability on both sides. B) The light transmittance of the metal thin film is 25% or more when light passes through the metal thin films on both the front and back surfaces. C) The electrical resistance per unit area of the metal thin film is 108Ω or less. D) The thickness of the metal thin film is +0A to 250A. E) A transparent protective layer containing an antistatic agent or not containing an antistatic agent is provided on the metal thin film with a thickness of 1 μm or less, if necessary. A sheet for packaging electronic components that is heat-sealable on both sides, and is characterized by meeting the requirements A) to E).